package com.atguigu.stack;

import java.util.Scanner;

/**
 * @author shkstart
 * @create 2021-08-09 14:23
 */
public class ArrayStackDemo {
    public static void main(String[] args) {
        //测试，创建一个栈
        Scanner scanner = new Scanner(System.in);
        ArrayStack stack = new ArrayStack(4);
        String key="";
        boolean loop=true;
        while (loop){
            System.out.println("show: 表示显示栈");
            System.out.println("exit: 退出程序");
            System.out.println("push: 表示添加数据到栈(入栈)");
            System.out.println("pop: 表示从栈取出数据(出栈)");
            System.out.println("请输入你的选择");
            key = scanner.next();
            switch (key){
                case "show":
                    stack.list();
                    break;
                case "push":
                    System.out.println("请输入添加的数据");
                    int value=scanner.nextInt();
                    stack.push(value);
                    break;
                case "pop":
                    try {
                        int res = stack.pop();
                        System.out.println("出栈的数据"+res);
                    } catch (Exception e) {
                        System.out.println(e.getMessage());
                    }
                    break;
                case "exit":
                    scanner.close();
                    loop=false;
                    break;
            }
        }
        System.out.println("退出程序");

    }
}
//创建一个栈
class ArrayStack{
    private int maxSize;
    private int [] stack;
    private int top=-1;
//创建一个构造器
    public ArrayStack(int maxSize) {
        this.maxSize = maxSize;
        stack = new int[this.maxSize];
    }
    //判断栈满
    public boolean isFull(){
        return top==maxSize-1;
    }
     //判断栈空
    public boolean isEmpty(){
        return top==-1;
    }
    //入栈
    public  void push(int value){
        if (isFull()){
            System.out.println("栈满");
            return;
        }
        top++;
        stack[top]=value;
    }
    //出栈
    public int pop(){
        if (isEmpty()){
//            System.out.println("栈空");
//            return 0;
            throw new RuntimeException("栈kong，没有数据");
        }
        int value=stack[top];
        top--;
        return value;
    }
    //遍历栈
    public void list(){
        if (isEmpty()){
            System.out.println("栈空，没有数据");
            return;
        }
        for (int i=top;i>=0;i--){
            System.out.println("stack["+i+"]="+stack[i]);
        }
    }

}
